text: Icosihenagonal Number | C ++ program to find nth Icosihenagonal number ; Function to find Icosihenagonal number ; Formula to calculate nth Icosihenagonal number ; Driver Code
code: #include <bits/stdc++.h> NEW_LINE using namespace std ; int Icosihenagonal_num ( int n ) { return ( 19 * n * n - 17 * n ) / 2 ; } int main ( ) { int n = 3 ; cout << Icosihenagonal_num ( n ) << endl ; n = 10 ; cout << Icosihenagonal_num ( n ) << endl ; return 0 ; }